Asymmetric Substitution of End‐Groups Triggers 16.34% Efficiency for All‐Small‐Molecule Organic Solar Cells

Abstract

Scheme 1. A) Synthesis procedure of compound 3. B) Synthesis procedure of SM-CA, SM-Reh, and SM-ID. C) Synthesis procedure of SM-CA-Reh and SM-CA-ID.

Alkoxy Substitution on Asymmetric Conjugated Molecule Enabling over 18% Efficiency in Ternary Organic Solar Cells by Reducing Nonradiative Voltage Loss

“…As a result, the PCE increases from 17.36% (binary film) to 18.14% (ternary film) when TB-S1-O is blended into the PM6:BTP-eC9 system due to the increase in V OC and J SC . In contrast, the incorporation of TB-S and TB-S1 formed an inferior morphology and thus failed to reduce voltage losses, resulting in poorer PCEs of 16 For TB-S1-O, the absorption maximum is blue-shifted by 20 nm from that of TB-S1. The optical band gaps of TB-S1 and TB-S1-O are calculated to be 1.57 and 1.62 eV, respectively, which are higher than that of TB-S (1.47 eV).…”

“…Organic photovoltaics (OPVs) with a bulk heterojunction (BHJ) have attracted abundant attention in the field of clean solar energy due to their promising advantages of solution processability, transparency, portability, and flexibility. − Due to the continuous design of novel nonfullerene acceptors, the power conversion efficiency (PCE) of binary OPVs under the illumination of 1 Sun intensity has been increased from ∼15% to ∼18%. − To further improve the performance of OPVs, a ternary strategy is considered to be an efficient and simple way. − However, many of these studies only focused on a single guest component without systematic research on analogues. Therefore, the correlation among the molecular structure of the third component, the active layer morphology, and the photovoltaic performance of the ternary device has rarely been clearly understood.…”

Over 17% efficiency all-small-molecule organic solar cells based on an organic molecular donor employing a 2D side chain symmetry breaking strategy

“…[7][8][9][10][11][12][13][14][15] Although the emergence of a large number of excellent small molecule acceptors, such as ITIC, IT-4F, Y6 and L8-Bo, presents a promising avenue for the future development of the performance of ASM-OSCs, their efficiency still lags far behind that of PSCs. [15][16][17][18][19][20][21][22] Generally, this critical problem is a reflection of the lack of suitable small molecule donors (SMDs) and existence of unknown structureproperties relationship, and therefore a better use of modular synthesis to regulate the electronic structure should be carefully considered.…”

Modulation of the Fluorination Site on Side-Chain Thiophene Improved Efficiency in All-Small-Molecule Organic Solar Cells

“…To date, the highest power conversion efficiency (PCE) record of binary OSCs (18.7%) and ternary OSCs (18.86%) is achieved by polymer organic solar cells (PSCs). Compared with polymer donors, all-small-molecule organic solar cells (ASM-OSCs) have a definite chemical structure, monodistribution, easy synthesis, and good reproducibility. − Although in recent years ASM-OSCs have made good progress in PCE performance, − they still lag behind their polymer counterparts. One of the critical reasons is the nonideal phase-separated morphology formed by the donor and acceptor.…”